1. Field of the Invention
The present invention relates to a radio terminal operation data write method and, more particularly, to a radio terminal operation data write method in a private mobile communication system constituted by multi-node PBXs (Private Branch Exchanges) each having a plurality of node exchanges that communicate with each other through a high-speed data line.
2. Description of the Prior Art
To meet demands for wide-area, versatile intra-enterprise information exchange, an intra-enterprise exchange network which allows wide-area private branch telephone exchange by connecting a plurality of PBXs through trunk lines and a private mobile communication system called a business PHS (Personal Handyphone System) that accommodates radio terminals by connecting radio base stations to the respective PBXs have recently become widespread.
In such a private mobile communication system, a plurality of radio base stations are distributed on the premises of a company, and radio terminals present in the radio areas of these radio base stations are connected to PBXs through the radio base stations, thereby allowing extension speech communication within the same PBX, extension speech communication with other areas using an intra-enterprise exchange network through leased lines, and outside speech communication upon connection with a public network through a central office line.
In this conventional private mobile communication system, when a radio terminal belonging to a PBX in a certain area is to be used in a radio area managed by a PBX in another area, roaming processing must be performed. This is because SYS (System)-IDs as system call codes assigned to the respective PBXs to ensure matching between radio terminals and systems for providing mobile communication services to the radio terminals differ from each other. According to such specifications, communication is inhibited between a radio terminal and a radio base station to which different SYS-IDs are assigned regardless of whether the same communication protocol is used. This indicates that in a mobile communication service in a public network, a radio base station and a radio terminal belonging to different communication companies cannot communicate with each other.
In a conventional PBX, since the PBX cannot control radio terminals other than those whose attribute information such as operation/management information is registered, SYS-IDs are assigned to these radio terminals to identify them to allow mobile communication only between a radio terminal and a radio base station having identical SYS-IDs. Even in a private branch exchange network within the same company, different SYS-IDs are assigned to PBXs constituting the network.
When the operation/management information written in a radio terminal, e.g., the extension number or the contents of an additional service, is changed, the changed data must be written in the radio terminal. In this case, therefore, the radio terminal must be present in the radio area of a radio base station connected to a PBX in which the radio terminal is registered. When data written in a radio terminal is to be changed during operation, a maintenance terminal connected to the corresponding PBX designates the radio terminal whose data is to be changed, and performs connection for the data change operation. When this connection for the data change operation is properly performed for the target radio terminal, the changed data set by the maintenance terminal is transferred to the radio terminal, and the data in the radio terminal is rewritten. If, therefore, the power to the radio terminal subjected to the data change operation is turned off, or the radio terminal is not present in the radio area supervised by a PBX to which the maintenance terminal is connected, this data change operation cannot be performed.
A technique of always performing proper roaming, including information between tenants in a case wherein one PBX accommodates a plurality of companies, in a private mobile communication system in which a plurality of PBXs constituting an intra-enterprise exchange network independently perform attribute registration for radio terminals is disclosed in Japanese Unexamined Patent Publication No. 9-247741. In addition, a technique of allowing a radio terminal that can be used both in a private branch exchange network and a public exchange network to terminate a call by using either of the telephone numbers assigned in the respective networks without considering the network in which the radio terminal is present is disclosed in Japanese Unexamined Patent Publication No. 10-70765.
In a conventional PBX, management/operation information required for exchange processing for extension numbers and the like is subjected to closed control within each PBX, and communication between PBXs is controlled by exchanging limited information through a trunk line connecting the respective PBXs. This also applies to the operation of radio terminals accommodated in a private mobile communication system formed by connecting radio base stations to such conventional PBXs. That is, since management/operation information required for exchange processing is subjected to closed control in each PBX, identical SYS-IDs cannot be assigned to different PBXs. For this reason, the use of a radio terminal is basically limited within the radio wave zone of a radio base station connected to a specific PBX in which the attribute information of the radio terminal is registered for management/operation.
Even if, therefore, a wide-area private mobile communication system is formed by using conventional PBXs, the operation of each radio terminal is greatly limited by the home PBX in which each radio terminal is registered. The user cannot therefore enjoy sufficient benefit from the portability of a radio terminal.
When attribute information registered in a radio terminal used at a remote place is to be changed at the home PBX (even if the radio terminal is present within the same intra-enterprise exchange network), this data cannot be changed unless the radio terminal is present within the radio area supervised by the PBX in which the attribute information on the radio terminal is registered. In such a case, according to the prior art, the radio terminal must be brought back to the radio area of the home PBX.
The present invention has been made to solve the above problem in the prior art, and has as its object to provide a radio terminal operation data write method in a private mobile communication system which allows writing terminal operation data written in the radio terminal by radio regardless of a radio area supervised by any PBX in an intra-enterprise exchange network constituted by a plurality of PBXs.
In order to achieve the above object, according to the first aspect of the present invention, there is provided a radio terminal operation data write method in a private mobile communication system including a multi-node PBX having a plurality of node exchanges connected to each other through a high-speed data line, comprising the steps of:
causing a node exchange to which a maintenance terminal is connected to specify a registration node exchange of a radio terminal from a logical extension number which is unique within the multi-node PBX and added to the radio terminal, acquire information on a current location area node exchange of the radio terminal through the high-speed data line, and request the current location area node exchange to write terminal operation data on the radio terminal; and
causing the current location area node exchange to acquire termination operation data on the radio terminal from the registration node exchange through the high-speed data line in accordance with the logical extension number and write the terminal operation data.
According to the first aspect, each of the plurality of node exchanges comprises a network database module for holding data common in the multi-node PBX, the terminal operation data on the radio terminal having the logical extension number is held in the network database module, and data specifying the registration node exchange for managing current location area information on the radio terminal is written in the network database module.
According to the first aspect, a better effect can be obtained if the node exchange to which the maintenance terminal is connected is a node exchange having a right to update the network database module.
In order to achieve the above object, according to the second aspect of the present invention, there is provided a radio terminal operation data write method in a private mobile communication system including a multi-node PBX having a plurality of node exchanges connected to each other through a high-speed data line, comprising:
the step of causing a maintenance terminal connected to a first node exchange of the plurality of node exchanges to designate a logical extension number unique in the multi-node PBX and added to a radio terminal with respect to the first node exchange and request the radio terminal to write terminal operation data by radio;
the step of causing the first node exchange to refer to a self-network database module holding data common in the multi-node PBX in accordance with the logical extension number so as to specify a third node exchange of the plurality of node exchanges in which the radio terminal operation data is registered;
the current location area node specifying step of causing the first node exchange to refer to a current information memory of the radio terminal of the third node exchange directly when the third node exchange coincides with the first node exchange or through the high-speed data line when the third node exchange differs from the first node exchange, thereby specifying a second node exchange of the plurality of node exchanges which corresponds to an area where the radio terminal is currently present;
the step of causing the first node exchange to output, to the second node exchange, a request to write operation data in the radio terminal by radio with the logical extension number being added to the request when the second node exchange differs from the first node exchange;
the step of causing the second node exchange to specify the third node exchange by referring to the self-network database module in accordance with the logical extension number;
the step of reading out data to be written in the radio terminal from operation data on the radio terminal held by the third node exchange directly when the second node exchange coincides with the third node exchange or through the high-speed data line when the second node exchange differs from the third node exchange;
the data write step of connecting the second node exchange to the radio terminal by radio and writing the data to be written in the radio terminal;
the step of causing the second node exchange to notify the first node exchange of a normal/abnormal end of the write processing when the second node exchange differs from the first node exchange; and
the step of causing the first node exchange to notify the maintenance terminal of the normal/abnormal end.
The first node exchange in the second aspect is a node exchange having a right to update the network database module.
According to the second aspect, the current location area node specifying step comprises causing the first node exchange to notify the maintenance terminal of a write failure and end processing when the current information memory indicates that the radio terminal is in a busy state.
According to the second aspect, the data write step comprises causing the second node exchange to notify the first node exchange of a write failure when the second node exchange cannot be connected to the radio terminal by radio, and causing the first node exchange to notify the maintenance terminal of the write failure and end processing.
As is obvious from the above aspects, according to the present invention, operation data can be written by radio at a maintenance terminal connected to a proper node exchange or a maintenance terminal connected to a node exchange for managing a network database regardless of the radio wave zone of a radio base station in which a radio terminal is connected to any node exchange in a multi-node PBX or the radio terminal registered in any node exchange. Therefore, to write operation data, any limitation need not be imposed on a radio terminal. In addition, any maintenance terminal need not be prepared for each node exchange.
The above and many other objects, features and advantages of the present invention will become manifest to those skilled in the art upon making reference to the following detailed description and accompanying drawings in which preferred embodiments incorporating the principles of the present invention are shown by way of illustrative examples.